This invention relates to a fastening adapter for fastening a protector, such as a hearing protector (or eye/face protector), to a helmet or other headgear.
Usually various kinds of protectors, such as hearing protectors, are used in connection with safety helmets made from plastic. In some (slotted) helmets, there are existing pre-fastening devices for fastening protectors. In such cases, the attachment of hearing protectors, for example, is relatively simple. However, the attachment of protectors to a general-purpose (non-slotted) helmet without pre-fastening devices is very much more difficult and indeed sometimes impossible.
In one known protector fastening adapter intended for a general-purpose helmet, the body part is fastened to the helmet with two bolts. For this purpose, two holes must be machined in the helmet. The body part fastened to the helmet is then set rotatably in a housing, to which the actual hearing protector is attached. The installation of the fastening adapter requires tools, due to the nuts and bolts, which makes the attachment more difficult. In addition, the nuts and the ends of the bolts protrude considerably inside the helmet. This can create a risk of injury to the user of the helmet, in the form of a bruising or an electrical shock. It is also difficult to position the holes by eye.
An object of the present invention is to create a simpler, more versatile, and easier to install fastening adapter for fastening protectors to a helmet or other headgear.
The present invention provides a fastening adapter for fastening protectors, such as hearing and/or face shield protectors, to a helmet or other headgear. The fastening adapter includes a body part to be attached to the helmet or headgear, and a housing connected to the body part and supporting the protector. At least one fastening device of the body part is fitted through a hole arranged in a wall of the helmet or headgear, and at least one fastening device locking device on the opposite side of the wall in relation to the body part for locking the fastening device and for pressing the body part onto the wall. The fastening device includes rotation prevention devices, to prevent body part from rotating in relation to the wall.
The fastening device is in two parts, both of which fastening devices are pins that extend through wall and which are set at a distance from each other. The first fastening device comprises a protrusion that forms part of body part and the second fastening device comprises an axle pin forming part of housing, which extends through both body part and wall, and to which axle pin locking device is intended to be fitted.
The fastening adapter includes a series of pairs of locking devices forming locks for different wall thicknesses. The series forming part of the fastening adapter has 2-6, most preferably 3-5 pairs of locking devices. In each lock of the series forming part, there is a hole for fastening the device to the bottom surface of which is at an angle in the longitudinal direction of the lock in relation to the base of the lock to be set against wall. The thickness of the lock tongue lying in the holes varies, the interval of variation being 2-5 mm, most preferably 2.5-4.5 mm, on the bottom surface of the hole.
Each of the locks forming part of the series is made from the same material as the fastening device. In the locking device there is a slot for attaching the locking device to the protrusion. At the end of the axle pin belonging to the housing there is a groove around the entire circumference of the axle pin for attaching the locking device. The depth of the groove is parallel to the radius of the axle pin and corresponds essentially to the dimensions of the locking device.
The locking device is intended to be set in the groove at essentially right angles to the axle pin by pressing it. The fastening adapter includes a jig for drilling holes in the aforesaid wall. The two drilling holes in the jig are set at the same distance from one another as the axle pin is from the protrusion. The first hole in the jig corresponds to the diameter of the protrusion and the second hole in the jig corresponds to the diameter of the axle pin. There is a measuring stick at the end of the jig with the first hole for positioning the jig in relation to the lower edge of the wall.
The fastening devices of a fastening adapter according to the invention are formed by the structural components of the fastening adapter. Thus separate fasteners, made form metal for example, are not required. In addition, the fastening adapter can be installed without tools, after holes have been drilled. The parts of the fastening adapter remaining inside the helmet are short and do not have detrimental protrusions. In addition, the locking device of the fastening member acts against a large surface area of the wall of the helmet. Further, the fastening adapter can be used to attach hearing protectors or a protection visor, or both simultaneously. The fastening adapter according to the invention can also be fitted in connection with a headband or any other construction supported by the head.
These and other features and advantages of the invention are described in greater detail in the following detailed description with reference to the accompanying drawings showing some embodiments of the invention.